Author round-table 009

Today's theme is easy puzzles. The guests this time are SAKAMOTO, Nobuyuki and Ryohei Nakai, both are great at making easy problems. From Nikoli we have NyanBaz and Nob. When you've read this article, it will become much more pleasant for you to solve easy problems, we are sure.

NyanBazWhen you make easy problems, do you aim at making them easy from the beginning?

SAKAMOTO, NobuyukiYes. When I plan to make easy problems I start making them that way. Sudoku is an exception. When I'm making a hard Sudoku, I sometimes change it to an easy problem halfway before it is finished.

Ryohei NakaiI aim at easy problems from the beginning, too. When I make a hard problem, sometimes it ends up becoming easy. The opposite never really happens.

NyanBazWhen you make an easy problem, don't you get an urge to add difficult solution methods?

SAKAMOTO, NobuyukiThat sometimes happens.

NyanBazThen, do you resist the urge or what?

SAKAMOTO, NobuyukiWell, I give in generally.

NyanBazReally? Do you? (laughs)

SAKAMOTO, NobuyukiSure. In that case I turn it into a hard problem. Then I make a new, different, easy problem.

NobSo when you are making an easy problem you sometimes change it to hard midway through?

SAKAMOTO, NobuyukiIt's very rare though. Let me explain it a little better. It is when I am making a problem and hit on a very good idea accidently. The idea not only has to be good but must also must be novel enough to make me want to develop it. Therefore it's a rare case.

Ryohei NakaiI think that there are a few more points to be careful about with easy problems than I think there are with hard problems. When you make a hard problem, you must be careful not to make it possible to be solved by an easy method from some point unless that is what you intend. But even if it is an easy problem and it has to be solved by hard methods, it is really no problem I think.

SAKAMOTO, NobuyukiI think differently. I don't want the solver to use a hard method in an easy problem. So I see that it is not possible.

Ryohei NakaiWell, for me, I think that I may include a place where only an expert solver would know to do it fast.

NobHmm. Let's think a step ahead. To an expert, you show a place that seems like an opening to be able to solve it fast. Then, it actually can't solved from there, but with beginner ways the whole puzzle is solved faster than an expert then could. That would be an interesting puzzle.

NyanBazThat'd be great.

Ryohei NakaiThat would be difficult however. How do you do it? (laughs)

NyanBazIt's sometimes said that an easy problem is just like exercises to keep the hands moving. How do you feel about that?

SAKAMOTO, NobuyukiI think that it's OK if it is like you just have to, like wave your hands. I don't think that all people enjoy all problems. It doesn't matter if there is someone who says that a problem for a beginner is not enjoyable.

Ryohei NakaiI want all people to enjoy everything if I can manage that. There are easy problems that can be enjoyed by everybody from beginner to expert.

NyanBazAre you sorry that I brought up this thing about just exercising the hands?

Ryohei NakaiMaybe a little bit. Perhaps it's a remark meaning that something is dull. I do not like it when it is put like that.

SAKAMOTO, NobuyukiWell, I don't think that a puzzle has to please everybody, and I don't mind whoever solves it. In fact, a beginner may not enjoy problems that another person calls easy problems, even if they are like the ones they call exercises to keep the hands in action.

NobI guess you may have a point there.

SAKAMOTO, NobuyukiOf course there is a point of contact where both experts and beginners can enjoy themselves. However, it's difficult to know where that point is. I try to give priority to the problems that a beginner can enjoy.

NobThere are people with the sense of values that a good puzzle it has to be hard. Such a person doesn't accept easy problems.

SAKAMOTO, NobuyukiSure. But even some of those people are bound to notice the merits of easy problems soon.

NobSuddenly one day they will understand why easy problems are great.

Ryohei NakaiIt the same with authors too. When I began to make puzzles, I didn't make easy problems.

NobEveryone starts out liking hard puzzles.

NyanBazThat can't be helped maybe. Anyone will want to use a method they have just discovered.

SAKAMOTO, NobuyukiWell, eventually everybody will notice the charms of easy problems for solvers and authors.

Ryohei NakaiI want as many people as possible to enjoy my work. To do that I show personality in the easy problems. For example, I use one method many times, over and over again.

NobThis is often the case in Ryohei's Shikaku problems. They are very good.

Ryohei NakaiThanks. But just now I have kind of run out of Shikaku ideas. I did all I can think of. (laughs) Joke of course. I want to follow some rules for my own reasons. If there isn't anything to guide me, all that I make becomes just hand waving.

NyanBazThere are many cases where even Nobuyuki repeats one method. In Slitherlink, you are good at patterns that don't let us make small loops.

SAKAMOTO, NobuyukiYes. But that pattern is not beginner-oriented. That is an easy method, but for a beginner it is hard to discover it. If anything, that is in problems for the experts who talk about hand waving.

NyanBazFor easy problems, there are some that are for beginners and some that are not for beginners.

SAKAMOTO, NobuyukiYes. I think that different standards can match our present standard of difficulty. Even if the standard says it uses only easy methods, it can be graded as medium because it is hard to find the next step somewhere.

NobKnowing how easy it is to find something is difficult. A problem may become quite easy if you hit on a point accidently. So we can't put that as medium difficulty. Our evaluation gives priority to the methods that are used.

SAKAMOTO, NobuyukiWell. Then, like me, someone who aims for the borderlines are bound to come up with ideas. For instance, where can I make it as hard as possible with only easy methods?

NobNobuyuki likes that kind of a challenge.

SAKAMOTO, NobuyukiYou understand me well. (laughs) I like aiming for the limits as well as making easy problems. I often contribute problems that shoot at a published limit. The other day there was such a problem published at the Botsu Bako, I thought that it was OK.

NobWhatever you say about perfection, that problem was for the Botsu Bako.

SAKAMOTO, NobuyukiSomething else, I think that It's difficult to make easy Sudoku. I worry about how many numbers we are permitted to put as starters.

NobPersonally I don't like problems with more than 30 starting numbers. They aren't illegal, but not attractive looking.

Ryohei NakaiI like the puzzles with few printed numbers, including in Sudoku. I think that a puzzle with few numbers is beautiful even a Slitherlink. I want to create a beautiful appearance even with an easy problem. Don't you agree?

SAKAMOTO, NobuyukiHmmmmmmm.

NobNobuyuki likes putting a lot of numbers in Slitherlink.

SAKAMOTO, NobuyukiThe best easy problems are those with few numbers, where they need all the methods for beginners, and then also are easy to solve. I can't make problems where all that fits. I think about how I can compromise. The first I give up on is the few numbers.

Ryohei NakaiI try to get a beautiful and attractive arrangement of numbers. When I am making a problem, I sometimes need to add numbers. In such cases I pay very careful attention to the arrangement.

NobThe hurdles are high, to get an attractive looking number arrangement, be careful to get a good feeling with the solution, and then the methods. Ryohei clears that wonderfully.

SAKAMOTO, NobuyukiI add numbers anywhere if troubled. (laughs)

NyanBazLet's change tracks. We use "Yasashii" for easy in Japanese. Yasashii also means gentle and kind. What about you, are you Yasashii? Please tell us by yourself.

Ryohei NakaiI'm very Yasashii.

NobWell. When you do board games with me, you make severe attacks, laughing. (laughs)

Ryohei NakaiGames with others are different. (laughs) I've been told that I'm good at taking care of others.

NyanBazWell, I think that Ryohei is a Yasashii person.

SAKAMOTO, NobuyukiMe, I wouldn't count me as a Yasashii person.

NobIn a previous interview, you said that you like to be contrary and raise hackles.

SAKAMOTO, NobuyukiThat's so. For example, I return minimal answers to elaborately polite emails from partners at work. I feel it is tiresome to dot every i and cross every t.

NyanBazThat is completely opposite to putting more numbers in your puzzles. (laughs)

NobWhatever. I think that an email should be short. I want emails to be brief. Well, anyway, Yasashii as a personal characteristic and Yasashii with a puzzle are different things.

SAKAMOTO, NobuyukiWhen people say that a person is Yasashii, there is a range of nuances included. When I make an easy puzzle, I make a problem where I have narrowed down the object. I don't consider anything except the beginner when I make a puzzle for beginners.

NyanBazWell said.

NobI think that a person who can make a good easy puzzle has to be very sociable. A self-satisfied person can't make an easy problem. People who can get their own thoughts neatly across are able to make good easy problems.

SAKAMOTO, NobuyukiWhen I make a puzzle, I think a lot about what I convey. I don't have confidence in the real world. (laughs)

NyanBazIt's important that what the author wants to convey is understood by the solver. Thank you for today. Please keep making a lot of good easy problems from now on.